Tool for working leather and like materials



May 30, 1933. R w MERRlcK 1,912,152

TOOL: FOR WORKING LEATHER AND LIKE MATERIALS Filed July 18, 1930 The invention will be Patented May 30, 1933 UNITED STATES PATENT orr ce FRANK W. MERRICK, OF DORCHESTER, MASSACHUSETTS, ASSIGNOR TO AMERICAN STAY COMPANY, OF EAST BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS TOOL FOR WORKING LEATHER AND LIKE MATERIALS Application filed July 18,

My invention relates to tools, particularly but not exclusively adapted for working leather, as for example trimming and bur- V nishing the edges of such material.

best understood from the following description when read in he light of the accompanying drawing of one embodiment of the invention, the scope of which latter will be more particularly pointed out in the appended claims. In the dr. wing: r Fig. 1 is an elevation, with parts broken away, of a tool constructed according to the invention;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a plan of the tool holder; Fig. 4 is a plan of the wabbling member W for vibrating the tool holder;

Fig. 5 is an elevation of an attachment for securing a knife to the tool holder;

Fig. 6 is a perspective of one form of knife for use with the device; and

Fig. 7 is a perspective of one form of M burnishing tool for use with the device.

Referring to the drawing, the embodiment of the invention illustrated is a hand held portable device which comprises an elongated, hollow handle 1 to be grasped by the 7 Bl) hand of the operator, at one end of which handle is rigidly carried a rotary electric motor 3, a flexible cable 5 being provided for connecting the motor to a suitable source of energizing electromotive force. The armature or driving shaft of the motor is indicated at 7, said shaft being disposed coaxially with the handle 1.

Herein, at its forward end the handle 1 is provided with an exteriorly screw threaded portion 9 on which is screw threaded a sleeve 11, the latter at opposite sides thereof having downwardly or forwardly projecting lugs 13, each of which lugs at its outer end is provided with a lateral projection 15. As shown, the device is provided with a tool holder 17 which is generally cup-- shaped with its lateral walls cut away as indicated at 19 to form lugs 21 located above the lateral projections 15, on which latter 6 the tool holder 17 is supported for swinging 1930. Serial No. 468,853.

movement by means of conical projections or pivot points 23 carried by the lugs 21 and received in recesses 25 formed on the upper or inner sides of the lateral projections 15.

Interiorly of the tool holder and sleeve 11 is shown a. cup-shaped member 27, which at diametrically opposite sides thereof has laterally projecting lugs 29 in quartering relation to the lugs 21, said lugs 29 at the low er or forward sides thereof having conical projections or pivot points 31 fitting recesses 33' (Fig. 3) in the upper marginal edge of the lateral wall of the tool holder, so that the cup-shaped member 27 may swing relative to said tool holder transversely thereof. Preferably, and as herein shown, the contact ends of the pivot points 23 and 31 are in a common plane as indicated by the line aa, Figs. 1 and 2.

WVith the construction above described it will be observed that the cup-shaped member 27 in effect has a universal joint connection or gimbal support on the sleeve 11, in consequence of which if the cup-shaped member is given a wabbling motion the tool holder will be swung on its pivot points 23 relative to said sleeve. For wabbling the member 27, the device as shown is provided with a rotary disk member 35 having an inclined lower or forward face 36, said disk member formed integrally with the shaft 37, which latter extends. axially through the handle 1 to, the rearward end of the latter, at which point it is formed with a flattened end portion 39 adapted to be detachably re-- ceived in the slot 41 formed in the end of the armature shaft 7 of the electric motor 3. As illustrated, the shaft 37 is rotatably supported in bearings 13 and 45 respectively at opposite ends of the handle member.

As shown, the lower or forward face 36 of the disk member 35 is inclined at a small angle to the axis of the shaft 37, say about two degrees in the proportion of parts shown, and between said forward face 36 and the opposed face constituting the bottom of the cup-shaped member 27 are antifriction members herein comprising the spherical rollers or. balls 47, similar anti- 100 friction members comprising the balls 49 being positioned between the upper or rearward face of the disk member and the opposed face of a bearing block 51 at the forward end of the handle member 1.

From the above described construction it will be observed that, when the electric motor is energized rapidly to rotate the disk 35, the latter, due to its inclined forward face, will cause a rapid wabbling movement of the cup-shaped member 27, the component of which movement transverse to the horizontal plane in which the pivot points 23 lie being imparted to the tool holder 17 for rapidly swinging the latter. Preferably, the spherical rollers 47, in contact with the inclined forward or lower face 36 of the disk member 35, have their centers in a plane, indicated by the line bb, Fig. 2, 5 which includes the pointed ends of the conical pivots 31 so as to eliminate or minimize the necessity of said rollers moving radially of the disk and cup-shaped member 27,

which tendency would exist if the plane 25, which includes the centers of the rollers were above or below the pointed ends of the pivots 31. As will be understood by those skilled in the art, the rollers 17, and likewise the rollers 49, are held in spaced relation circumferentially of the disk member 35 by retainers 53, and by keeping said rollers 17 in the same plane as the points of the pivots 31 said balls merely roll in a circular path about the axis of the disk member 35 without 3 5;. having imparted thereto any component of movement radially of this member. This action minimizes wear.

As shown, the cup-shaped member 27 provides a container for oil or grease for lubricating the bearings enclosed by said cup. Herein, for preventing leakage of lubricant the upper marginal edge of the cup-shaped member bears against a ring of felt or other suitable resilient material carried in J the space between the periphery of the bearing block 51 and inner walls of the sleeve 11. The resiliency of the ring 55 permits the marginal edge of the cup always to be in contact with the ring so as to close the cup against leakage of lubricant.

The device above described is particularly useful for trimming and burnishing the exposed edges of seams in leather moccasins and for uses in like situations. The upper of such a moccasin is indicated in Fig. 2, said upper comprising the leather sheets 57 and 59 united by a seam 61 exposed on the outer side of said upper. Heretofore it has been possible to trim such a seam only by means of a hand knife, with which it is extremely difficult to secure satisfactory results, especially with certain grades of leather, as for example so-called elm tanned leather. For such trimming the 65 machine may be used to actuate a knife 63,

the cutting edge of which is notched as indicated at 65 (Fig. 6) for embracing the seam. Herein, for securing the knife to the tool holder 17, the latter is provided with a knife blade holder comprising a base 67 having openings 69 through which may pass screws 71 for securing said base to the under side of the tool holder. As shown, the downwardly curved shank 73 of the knife blade holder is provided with a pin 75 for insertion into, an opening 77 in the knife blade so as properly to position the latter, the shank 73 being further provided with a screw threaded opening 79 for receiving a screw 81 the shank of which extends through an opening 83 in the knife blade. For guiding the knife relative to the seam, a guide member 85 is herein provided, which guide member is secured to the sleeve 11 by screws 87 and has a foot 89 the outer edge of which engages with the side of the seam.

For burnishing the seam, the burnishing tool shown by Fig. 7 may be substituted for the knife 63 and knife blade holder 73, said burnishing tool as shown comprising a base 91 having openings 93 through which the screws 71 may be passed for securing said base to the tool holder. As shown, the base 91 has secured thereto a shank 95 on the lower end of which is a grooved burnishing part 97 for engaging the edge portion of the seam.

As an example of the proportioning of parts, but without limitation thereto, I have found that for trimming leather as above described, and for analogous uses, extremely satisfactory results will be secured, when the amplitude of vibration of the cutting edge of the knife is in the order of of an inch and the frequency of vibration is about 2000 per minute.

It will be understood that, if desired, the casing of the motor or handle of the tool may be provided with a conveniently located electric switch for deenergizing the motor, so that the operator can readily make and break the circuit when the tool is in use, which will save undue wear and heating of the parts. Also, if desired, the motor may be omitted, and the tool be driven 5111 by a flexible shaft driven by an independently mounted motor or other source of power, and in general wide deviations may be made from the embodiment of the i11vention herein described without departing 1 .1 from the spirit of the invention.

I claim:

1. A device of the character described having, in combination, a supporting part, a tool holder mounted upon said part for 1 swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means for imparting a wabbling movement to said member.

ago

transverse to the swinging movement of said holder and means comprising a rotary part cooperating with said member for im- Jarting a wabbling movement thereto.

4. A device of the character described having, in combination, a supporting part, a tool holder mounted upon said part for swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means comprising a rotary part having a face inclined to its axis of rotation cooperating with said member for imparting a wabbling movement thereto.

5. A device of the character described having, in combination, a supporting part, a tool holder mounted upon said part for swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means for imparting a wabbling movement to said member, said means comprising a rotary part having a face inclined to its axis of rotation and opcratively having a bearing upon an opposed face on said member.

6. A device of the character described having, in combination, a supporting part, a tool holder mounted upon part for swinging movement, a member mounted on said tool holder for swinging movement transvere to the swinging movement of said holder, and means for imparting a wabbling movement to said member, said means com prising a rotary disk-like part having a face inclined to its axis of rotation and operatively having a bearing upon an opposed face on said member.

7. A device of the character described having, in combination, a supporting'part, a tool holder mounted upon said part for swinging movement, a member mounted on said tool holder for swinging movement trans-V verse to the swinging movement of said holder, means for imparting wabbling movement to said member, said means comprising a rotary disk-like part having a face inclined to its axis of rotation in spaced relation toa parallel face on said member, and anti-friction rollers between said faces.

8. A device of the character described having, in combination, a supporting part, a tool holder mounted upon said part for swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means for imparting a wabbling movement to said member, said means comprising a rotary disk-like part having a face inclined to its axis of rotation and operatively having a bearing upon an opposed face on said member, the latter formed to provide an oil receiving cavity receiving said disk-like part.

9. A device of the character described having, in combination, a supporting part, a tool holder mounted upon said part {for swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means for imparting a Wabbling movement to said member; said means comprising a rotary disk-like part having opposed faces, one of which faces is normal to its axis of rotation and operatively has a bearing upon said supporting part, and the other of which faces operatively has a bearing upon said member.

10. A device of thecharacter described having, in combination, a supporting part, a tool holder mounted upon said part for swinging movement, a member mounted on said tool holder for swinging movement transverse to the swinging movement of said holder, and means for imparting a wabbling movement to said member; said means comprising a rotary disk-like part having opposed faces, one of which faces is normal to its axis of rotation'and operatively has a bearing upon said supporting part, and the other of which faces operatively has a bearing upon said member; an annular part surrounding said disk-like part and cooperating with said supporting part and member to form an oil reservoir in which said disklike part is contained.

11. A portable hand held device of the character described having, in combination, an elongated handle member having at one end thereof a rotary electric motor the shaft of which is arranged longitudinally of said member, said member at the opposite end thereof operatively carrying a tool for swinging movement transverse to said memher, a part operatively connected to said tool for swinging movement transverse to the swinging movement of said tool, and means driven by said motor for wabbling said part.

In testimony whereof, I have signed my name to this specification.

FRANK W. MERRIOK. 

